A novel bisphthalonitrile monomer containing allyl groups (DBPA‐Ph) had been synthesized via the reaction of diallyl bisphenol A (DBPA) and 4‐nitrophthalonitrile. The chemical structure of DBPA‐Ph was confirmed by 1HNMR, 13CNMR, and FTIR spectroscopy. The curing behaviors and processability of DBPA‐Ph were studied by differential scanning calorimetry (DSC) and dynamic rheological analysis. The monomer manifested a two‐stage thermal polymerization pattern. The first stage was attributed to the polymerization of allyl groups and the second to the ring‐form polymerization of cyano groups. The result of dynamic rheological analysis indicated the monomer had wide curing window and the self‐catalyzed curing behavior. DBPA‐Ph polymers were prepared from the thermal polymerization with short curing time, showing high glass transition temperature (>350°C) and attractive thermal decomposition temperature (>430°C). The outstanding glass transition temperature, desirable thermo‐oxidative stabilities, good processability and sound process conditions could provide more applications to the DBPA‐Ph polymers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41203.

An easy and efficient approach by using carboxyl functionalized CNTs (CNT-COOH) as nano reinforcement was reported to develop advanced thermosetting composite laminates. Benzoxazine containing cyano groups (BA-ph) grafted with CNTs (CNT-g-BA-ph), obtained from the in situ reaction of BA-ph and CNT-COOH, was used as polymer matrix and processed into glass fiber (GF)-reinforced laminates through hot-pressed technology. FTIR study confirmed that CNT-COOH was bonded to BA-ph matrices. The flexural strength and modulus increased from 450 MPa and 26.4 GPa in BA-ph laminate to 650 MPa and 28.4 GPa in CNT-g-BA-ph/GF composite, leading to 44 and 7.5% increase, respectively. The SEM image observation indicated that the CNT-COOH was distributed homogeneously in the matrix, and thus significantly eliminated the resin-rich regions and free volumes. Besides, the obtained composite laminates showed excellent thermal and thermal-oxidative stabilities with the onset degradation temperature up to 624 C in N 2 and 522 C in air. This study demonstrated that CNT-COOH grafted on thermosetting matrices through in situ reaction can lead to obvious mechanical and thermal increments, which provided a new and effective way to design and improve the properties of composite laminates.

Much attention has been recently focussed on the melt impregnation of thermoplastic polymers as a consequence of the difficulty involved in driving viscous polymer melt into a tightly packed fiber bundle. This work studies an impregnation process consisting a series of staggered cylindrical pins in a melt pool. A numerical model for evaluating the pressure generation in the wedge region between the roving/pin, the impregnation velocity of the melt through the glass mesh, and the resulting impregnation depth along the wedge is developed using relationships for pressure build-up in foil bearings and Darcy's law. The model results are compared with experimental melt impregnation data. The model adequately predicts the effect of melt impregnation process conditions on impregnation quality.

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